These packages can be install and flash manually to to Iconia A500. You may just select the right fimware version of your phone like for example if your A500 16GB wifi only phone currently running 1.104.02 you can flashed the OTA update version 1.144.07.

How to flash?
- You have to downloadAcer Update Decryter to decrypt these firmware.
- Once the file is already decrypted, Extract the update.zip from it,
- Copy it to external SDCard (does not work on internal memory)
- Boot your Iconia A500 tablet by pressing Volume Down & Power. Then update will be launch automatically. Read the full guides at XDA-developer for further instruction.